SPINACH, the vegetable loved by Popeye, could
prove to be a cure for certain forms of blindness.
Doctors now believe that an eye-drop containing a
protein taken from spinach could be soon available
to treat the millions of people suffering from
age-related macular degeneration of the eye and
Age-related macular degeneration is a common eye
disease associated with ageing that gradually
destroys sharp central vision.
The macula is made up of millions of light-sensing
cells in the middle of the retina. When these cells
degenerate, vision is impaired and if the disease
progresses quickly, blindness follows.
Retina pigmentosis is a genetic disease which
affects about one person in 4,000. Sufferers develop
night blindness, then tunnel vision and finally loose
their colour and day vision. In the Western world it
is the most common cause of blindness in people
under the age of 70. The cause is unknown.
Scientists working for the US government discovered
that the protein, known as Photosystem One, was
able to generate electrical energy. That energy can
trigger light-receiving cells to function, enabling the
retina to "see" images again.
A team of surgeons working at the Doheny Eye
Institute at the University of Southern California with
Dr Eli Greenbaum, of the Oak Ridge National
Laboratory, has already established that
light-receiving cells in the eyes of the blind can be
triggered to work again.
When pinhead electrodes were implanted in blind
people they were able to see images and patterns.
Now the Doheny team believes that the spinach
protein is capable of setting off a chemical reaction
which will stimulate the eye cells.
Dr Greenbaum said: "We have found that the
protein from the spinach is able to make up to one
volt and sustain that over a long period."
"Although the neural wiring from the eye to the
brain is intact in diseases such as macular
degeneration, the cells at the front of their eyes lack
photo-receptor activity to transmit the information
that makes images."
He added: "We believe that Photosystem One can
start that process again. We have established the
mechanism that could help so many people who are
blind or semi-blind to see again."
Dr Greenbaum is planning experiments with rats and
mice next year and, if successful, human clinical trials
in about two years.
13 October 2001: The spread of blindness 'is reduced by